список содержимого каталога (list directory contents)
Описание (Description)
For each operand that names a file of a type other than directory
or symbolic link to a directory, ls shall write the name of the
file as well as any requested, associated information. For each
operand that names a file of type directory, ls shall write the
names of files contained within the directory as well as any
requested, associated information. Filenames beginning with a
<period> ('.') and any associated information shall not be
written out unless explicitly referenced, the -A or -a option is
supplied, or an implementation-defined condition causes them to
be written. If one or more of the -d, -F, or -l options are
specified, and neither the -H nor the -L option is specified, for
each operand that names a file of type symbolic link to a
directory, ls shall write the name of the file as well as any
requested, associated information. If none of the -d, -F, or -l
options are specified, or the -H or -L options are specified, for
each operand that names a file of type symbolic link to a
directory, ls shall write the names of files contained within the
directory as well as any requested, associated information. In
each case where the names of files contained within a directory
are written, if the directory contains any symbolic links then ls
shall evaluate the file information and file type to be those of
the symbolic link itself, unless the -L option is specified.
If no operands are specified, ls shall behave as if a single
operand of dot ('.') had been specified. If more than one
operand is specified, ls shall write non-directory operands
first; it shall sort directory and non-directory operands
separately according to the collating sequence in the current
locale.
Whenever ls sorts filenames or pathnames according to the
collating sequence in the current locale, if this collating
sequence does not have a total ordering of all characters (see
the Base Definitions volume of POSIX.1‐2017, Section 7.3.2,
LC_COLLATE), then any filenames or pathnames that collate equally
should be further compared byte-by-byte using the collating
sequence for the POSIX locale.
The ls utility shall detect infinite loops; that is, entering a
previously visited directory that is an ancestor of the last file
encountered. When it detects an infinite loop, ls shall write a
diagnostic message to standard error and shall either recover its
position in the hierarchy or terminate.
